Add subscriber label to contact

Looking to create an option of different newsletter preferences. I’ve seen some threads address this but not quite what I want.
This is the form I created in the “subscriber form” (see below). The tool allows me to add a new field easily, but then the check selections don’t show up in the contact information. What I’d like is for the check boxes to then add the contact to the corresponding label so that I can send them only the newsletters they are interested in getting. Any idea how to do this?

The labelContact API might be of use to you:

If you’re using Ascend by Wix to send emails, you can address your newsletter to contacts with specific “labels” only.

For each form submission, create a contact in the backend , and then add the labels to the contact that corresponds to the checked newsletters.